1. Field of the Invention
The present invention relates generally to an apparatus for drilling holes, and more particularly to an apparatus for drilling holes in composite materials with the depth of the holes being controllable.
2. Description of the Prior Art
In composite structures, holes sometimes must be drilled so that resin may be injected to fill delaminations, cracks, or voids that have developed. The holes must be drilled to a specific depth and in a specific location so that the resin introduced at the composite surface can flow through the drilled hole to fill the delamination, crack, or void.
Drills have been utilized previously that were capable of drilling through the composite material, but the depth of the hole depended upon the operator's discretion. The operator was thus forced to guess when the drilling should cease in order to have a hole drilled to the delamination, crack, or void without having the hole be either too short or too long. As the size of the delamination, void, or crack to be filled decreases, sometimes to 0.002 inches, it is extremely difficult for the operator to accurately gauge the depth of the hole.
It would be desirable to develop an apparatus for drilling composite materials that was capable of controlling the drilling depth. Furthermore, it would be desirable for the apparatus for drilling composite materials to be portable and be able to operate over a wide range of drilling speeds.